President Barack Obama's much-publicized search for a dog that wouldn't trigger daughter Malia's allergies put a spotlight on hypoallergenic dogs.
But less attention has been paid to cats, even though cat allergies are twice as common as allergies to dogs, according to the Asthma and Allergy Foundation of America.
So is there such a thing as a hypoallergenic cat?
The short answer is scientists don't know. If you have allergies and want a cat, it may be possible to find one that won't bother you. But experts can't explain why.
Anatomy of an Allergy
People with cat allergies react to a protein in the animal's saliva, skin, and urine. The allergen collects on the cat's fur when the animal licks itself and comes off in tiny flakes of skin that glom onto walls, carpet, and furniture or stay in the air. A cat's lick or scratch can cause skin welts or itchiness. In the nose and lungs, the protein causes itchy, watery eyes and nasal congestion and can lead to asthma.
The allergens are so powerful that they can hang around for months, causing effects long after the cat is gone.
Some cats secrete less of the protein, some cats put out less saliva, and some cats produce less dander. But all cats make the allergen in some form -- and a tiny amount can cause a lot of symptoms, depending on how clean you keep your house and how often you're around the animal, says Robert Zuckerman, MD, an allergy and asthma specialist in Harrisburg, Pa.
"Even a cat that has a little bit of allergen can cause allergy if you have enough exposure to it," Zuckerman says.
The other variable is your immune system. Maeve O'Connor, MD, an allergy, asthma, and clinical immunologist in Charlotte, N.C., says one person can hold a cat and have no symptoms, while another has an asthma attack standing near a person with cat dander on their clothes.
Still, some allergy sufferers find their symptoms don't flare up around certain cats. Maybe they can tolerate domestic shorthairs but not oriental breeds -- or vice versa. Some can pet a white cat but start sneezing as soon as they touch a dark gray or black one. Many patients report they can only handle being around Siberian cats.
But research offers only clues, not answers.
"There are no scientifically validated studies to show that any particular breed of cat, whether it's Siberian or anything else, is 'hypoallergenic,'" says Martin Chapman, PhD. He's the president of Indoor Biotechnologies, an allergy testing company that provides the kits for most of the world's studies on allergen exposure.
Short of scientific proof, breeders have noted that Siberian cats seem less likely to trigger allergies.
Jen Van Horn Jeffers of New Hampshire suffered the classic symptoms for years. Picking up most cats left her with hives, shortness of breath, itchy, watery eyes, and a scratchy throat. But surrounded by about 20 Siberian cats at a breeder's home, her symptoms were gone.
"I couldn't believe it," says Jeffers, 37, who recently purchased her second Siberian. "I love cats. When you've never been able to have one, it's like 'Wow, this is so cool.'"
Siberian breeders have submitted samples to Chapman's company and found relatively low levels of the offending protein in their saliva. But Chapman cautioned against generalizing, in part because the lab didn't test samples from breeders of other cats to compare.
The short-haired Devon Rex and Cornish Rex cats are thought to be less allergenic because they have less hair to shed, resulting in fewer saliva-coated particles in the air.
Some people with allergies can also tolerate the hairless Sphynx. That's likely because the cat needs to be bathed or wiped down frequently, which reduces its allergen-carrying dander, says Lorraine Jarboe, DVM, president of the American Association of Feline Practitioners.
Making a Hypoallergenic Cat
In 2006, a company called Allerca made headlines when it announced that it had bred the world's first hypoallergenic cat. Now known as Lifestyle Pets, the company says its cats -- which cost $8,000 to $27,000 -- naturally produce a modified protein that doesn't trigger most allergies.
Founder Simon Brodie says he has sold cats to more than 350 clients. However, the company has also faced allegations of fraud by customers who said they forked over the money and never got a cat -- or a refund.
Scientists want Brodie to let them independently verify his claims. Brodie says the satisfied customers speak for themselves.
Judy Smith, 37, of Westwood, Mass., who suffers from asthma and severe cat allergies, bought her first cat from Brodie in 2007 for about $7,000. She recently got a second.
Smith says they're not 100% hypoallergenic; she occasionally gets itchy eyes if she touches her face after hugging them. But it's nothing like the symptoms that flare up around other people's cats.
"They sit on my lap and sleep with us in bed and lick my face and I play with them all the time," Smith says. "It's really worth every penny because otherwise I wouldn't be able to even have one cat, let alone two in my house."
Another company, Felix Pets, claims to be engineering a hypoallergenic cat by removing the gene that makes the major cat allergen.
But Zuckerman, who is not involved with either company, says, "It's a difficult task to eliminate a gene from an animal." Plus, Zuckerman notes that scientists also don't know why the cat produces the protein, so it's unclear how removing the gene would affect the cat.
Even if you find a cat that doesn't bother you, Zuckerman recommends taking certain precautions:
- Have someone without allergies wipe the cat frequently with a damp towel.
- Vacuum frequently and thoroughly with a sweeper that has a HEPA filter.
- Keep the cat out of the bedroom.